Hot Test Results (~45°C Ambient)

The performance of the ASUS TUF Gaming 850W Gold PSU degrades measurably when the ambient temperature is high but not exceedingly so. Its average energy conversion efficiency across the nominal load range drops to 89.9% with an input voltage of 230 VAC and down to 88.8% with an input voltage of 115 VAC, translating to an average efficiency drop of 1% regardless of the input voltage. The drop is consistent across the entire load range, suggesting no significant thermal stressing exists on the unit’s major components.

Despite the very high ambient temperature, the ASUS TUF Gaming 850W Gold will still operate fanless when lightly loaded. As a result, the internal temperatures of the unit are high – significantly high for a PSU with that kind of output and efficiency. Component temperatures reach over 100 °C when the PSU is heavily loaded for prolonged periods under these conditions. There is a slightly higher efficiency degradation under maximum load than the rest of the operating range, suggesting marginal thermal stress on active components, but the effect is slight.

Even with an ambient temperature greater than 45°C, the fan does not start at all when the load is lower than roughly 220 Watts. Once it starts, it is relatively quiet at first but quickly speeds up to cope with the cooling requirements of the unit, becoming clearly audible at half load and reaching high noise figures at loads greater than 600 Watts. Regardless, it never reached its maximum speed, even when the unit was operating at maximum capacity.

Cold Test Results (~26°C Ambient) Power Supply Quality & Conclusion
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  • Threska - Thursday, August 31, 2023 - link

    Minimalistic in it's sameness. Pretty much only thing bringing them out of that is different transistors and RGB.
  • ingwe - Thursday, August 31, 2023 - link

    Given the positive conclusion, I think the article headline/title should be changed. Based on that I expected a negative take on the product based on that. Meaning I expected "tough but fair criticism" based on the price/performance etc.
  • Oxford Guy - Thursday, August 31, 2023 - link

    He was obligated to have Tough in there because the product is marketed with that word ('TUF').

    Tough and Fair folk are Great Wall military types, you know.
  • Igor_Kavinski - Friday, September 1, 2023 - link

    Thank you so much for the great review!
  • Samus - Saturday, September 2, 2023 - link

    The only thing missing from this PSU is a fan profile switch - something present on many other PSU's in this class, Seasonic "Hybrid Mode" EVGA "ECO Mode" etc.

    This would greatly help my anxiety when running in the 500w power envelope (which is often where my systems hovers while gaming (depending on the game) with in i7-12700k and RTX 4070Ti. CPU hits PL1 sometimes in Battlefield 2042 but almost no games hit PL2, which would increase the system total power consumption to 650w assuming the GPU was loaded up too. Furmark + CPU burn simulates this, and to get a total system load draw, I have a disk IO torture test running with all SSD's, HDD's, and a few USB 3.0 flash drives to pull some bus power.

    This makes an 850w PSU unnecessary for my system, but a little headroom is good for efficiency, longevity and upgradability. The problem is longevity is questionable if this thing is constantly running hot and the fan doesn't turn on at 500-watt sessions. The capacitors especially are rated for a fixed amount of hours at 95-105c and the further you stay away from that range, the longer the cap will last. And tin\lead free solder is not good with heat cycling above 105c that this PSU can hit if ambient temps are high.

    Overall its a great product ruined by a bad cooling curve. The fan itself is questionable considering it doesn't even reach its 'rated' RPM. Is it just me or is the appeal of a silent PSU when drawing 500+ watts of power a weird concept. More than likely you are in a game (no single CPU and disk IO will draw 500w) except in edge cases where this PSU is oddly used in a workstation for GPU-based rendering. And if you are in a game, your other components cooling systems are going to greatly overpower whatever sound pressure this PSU's fan hits.
  • Claudius-07 - Sunday, September 3, 2023 - link

    Can someone please explain to an old person: I have a new mobo and it has DDR5 and has 2 8 pin power connectors at the top of the mobo for CPU power. I have the new mobo and a new CPU and the RAM. The video card I bought is a RX 6800. It also has 2 8 pin power connectors. I do not understand, do I need a NEW Power supply ATX 3.0 and PCI5? Do I just need a PS that has at least 4, 8 pin connectors?
  • E.Fyll - Monday, September 4, 2023 - link

    Any PSU with two EPS and two PCI Express connectors will do. Note that EPS and PCI Express connectors are different, even if the number of pins is the same. That system does not need an ATX 3.0 compliant unit nor a PCI-E 5.0 connector.
  • RomanPixel - Wednesday, September 6, 2023 - link

    Aww man, they didn't change the 12VHPWR connector to a 12V-2x6 before pushing this out.

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